This invention relates, in general, to a timing mechanism and in particular to a timing mechanism particularly adaptable for controlling a laundry dryer through a timed fabric treatment cycle.
Some automatic clothes dryers include an anti-wrinkle control system that provides for rearranging and refluffing permanent press fabrics every few minutes if they are not removed from the dryer at the end of a permanent press cycle, a buzzer sounds to remind a housewife, for example, that her clothes are ready. If she is busy or out of the home, the anti-wrinkle control starts the dryer at predetermined intervals, for example every five minutes and tumbles the clothes for a predetermined interval, for example, 10 seconds. At the end of each 10 seconds of tumbling, the dryer again buzzes to remind the housewife to remove the clothes. The dryer continues to "nag" in this manner for a predetermined period of time, for example, up to two and one half hours. However, for the times illustrated, total running time for the dryer would only be five minutes.
In U.S. Pat. No. 4,103,119 issued July 25, 1978 there is described and claimed a timing mechanism wherein two separate sets of cams are independently rotated by a single motor drive having a gear train with two separate outputs. While the timing mechanism very adequately provides a separate "pulsing cycle" for anti-wrinkle control, it does present one or two problems with regard to the manner in which the "pulser cam" is constructed and the manner in which it is coupled to the drive motor. More particularly, the pulser cam is of a two piece construction which adds to the cost of the timing mechanism and which in conjunction with the manner in which the cam is coupled to the motor drive makes it difficult under certain circumstances to achieve a fast make and break between electrical contacts. This is especially critical where, as in the present application, a pulsing action is required.